Entanglement in Ising Chain with Inhomogeneous Magnetic Field

We have numerically calculated the thermal entanglement of a two-qubit system at low temperatures in a isotropic Ising chain under an inhomogeneous magnetic field. It is shown that in the homogeneous magnetic field, the two-qubit system has entangled states. It is concluded that the presence of the inhomogeneity in the magnetic field plays an effective role on the entangled states. Finally, it is suggested that the
inhomogeneity in the magnetic field can be used to create two separated entangled formations in a two-qubit system.